2003 JEEP GRAND CHEROKEE fuse block

JUNCTION BLOCK C2 (LHD) - BLACK 52 WAY
CAV CIRCUIT FUNCTION
1 X3 22GY/OR HORN RELAY CONTROL
2- -
3 L39 20LB FOG LAMP RELAY OUTPUT
4- -
5 L61 20TN/LG LEFT TURN SIGNAL
6- -
7- -
8 V6 16DB FUSED IGNITION SWITCH OUTPUT (RUN-ACC)
9 V6 16DB (GAS) FUSED IGNITION SWITCH OUTPUT (RUN-ACC)
10 L62 18BR/RD RIGHT TURN SIGNAL
11 F991 20OR/DB FUSED IGNITION SWITCH OUTPUT (RUN-START)
12 L39 20LB FOG LAMP RELAY OUTPUT
13 - -
14 - -
15 V16 22VT WIPER HIGH/LOW RELAY CONTROL
16 - -
17 - -
18 - -
19 - -
20 L7 20BK/YL PARK LAMP RELAY OUTPUT
21 L7 20BK/YL PARK LAMP RELAY OUTPUT
22 - -
23 - -
24 F37 16RD/LB (EXCEPT BASE) FUSED B(+)
25 F22 20WT/PK FUSED IGNITION SWITCH OUTPUT (RUN)
26 L60 20TN RIGHT TURN SIGNAL
27 F45 20YL/RD FUSED IGNITION SWITCH OUTPUT (START)
28 V55 16TN/RD WIPER PARK SWITCH SENSE
29 - -
30 - -
31 F72 16RD/YL FUSED B(+)
32 M1 20PK/RD FUSED B(+)
33 V55 16TN/RD (GAS) WIPER PARK SWITCH SENSE
34 - -
35 - -
36 A146 12OR/WT FUSED B(+)
37 - -
38 L34 18RD/OR FUSED RIGHT HIGH BEAM OUTPUT
39 L43 18VT FUSED LEFT LOW BEAM OUTPUT
40 - -
41 - -
42 F20 18DB/PK FUSED IGNITION SWITCH OUTPUT (RUN)
43 F12 20DB/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
44 - -
45 A146 12OR/WT FUSED B(+)
46 - -
47 F32 20PK/DB FUSED B(+)
48 - -
49 L44 18VT/RD FUSED RIGHT LOW BEAM OUTPUT
50 L33 18RD FUSED LEFT HIGH BEAM OUTPUT
51 - -
52 F60 14RD/WT (EXCEPT BASE) FUSED B(+)
8W - 80 - 88 8W-80 CONNECTOR PIN-OUTWJ

JUNCTION BLOCK C2 (RHD) - BLACK 52 WAY
CAV CIRCUIT FUNCTION
1 X3 22BK/RD HORN RELAY CONTROL
2- -
3 L39 20LB FOG LAMP RELAY OUTPUT
4- -
5 L61 20TN/LG LEFT TURN SIGNAL
6- -
7- -
8 V6 16DB FUSED IGNITION SWITCH OUTPUT (RUN-ACC)
9 V6 16DB (GAS) FUSED IGNITION SWITCH OUTPUT (RUN-ACC)
10 L62 20BR/RD RIGHT TURN SIGNAL
11 F991 20OR/DB (GAS) FUSED IGNITION SWITCH OUTPUT (RUN-START)
12 L39 20LB FOG LAMP RELAY OUTPUT
13 - -
14 - -
15 V16 22VT -
16 - -
17 - -
18 - -
19 - -
20 L7 20BK/YL PARK LAMP RELAY OUTPUT
21 L7 18BK/YL PARK LAMP RELAY OUTPUT
22 - -
23 - -
24 F37 16RD/LB FUSED B(+)
25 F22 18WT/TN FUSED IGNITION SWITCH OUTPUT (RUN)
26 L60 20TN RIGHT TURN SIGNAL
27 F45 20YL/RD FUSED IGNITION SWITCH OUTPUT (START)
28 V55 16TN/RD WIPER PARK SWITCH SENSE
29 - -
30 - -
31 - -
32 M1 20PK/RD FUSED B(+)
33 V55 16TN/RD (GAS) WIPER PARK SWITCH SENSE
34 - -
35 - -
36 A146 12OR/WT FUSED B(+)
37 - -
38 L34 18RD/OR FUSED RIGHT HIGH BEAM OUTPUT
39 L43 18VT FUSED LEFT LOW BEAM OUTPUT
40 - -
41 - -
42 F20 18DB/PK FUSED IGNITION SWITCH OUTPUT (RUN)
43 F12 20DB/WT (GAS) FUSED IGNITION SWITCH OUTPUT (RUN-START)
44 - -
45 A146 12OR/WT FUSED B(+)
46 - -
47 F32 20PK/DB FUSED B(+)
48 - -
49 L44 18VT/RD FUSED RIGHT LOW BEAM OUTPUT
50 L33 18RD FUSED LEFT HIGH BEAM OUTPUT
51 - -
52 F60 16RD/WT FUSED B(+)
WJ8W-80 CONNECTOR PIN-OUT 8W - 80 - 89

JUNCTION BLOCK C3 - BLACK 52 WAY
CAV CIRCUIT FUNCTION
1 F22 20WT/PK FUSED IGNITION SWITCH OUTPUT (RUN)
2- -
3 L60 20TN RIGHT TURN SIGNAL
4 L302 20LB/YL RIGHT TURN SWITCH SENSE
5 L61 20TN/LG LEFT TURN SIGNAL
6 L91 20DB/PK HAZARD SWITCH SENSE
7- -
8 L305 20LB/WT LEFT TURN SWITCH SENSE
9- -
10 L309 20PK/LG HIGH BEAM RELAY CONTROL
11 F23 18DB/YL FUSED IGNITION SWITCH OUTPUT (RUN)
12 F22 20WT/PK FUSED IGNITION SWITCH OUTPUT (RUN)
13 - -
14 F85 16VT/WT FUSED B(+)
15 C79 20BK/WT FUSED REAR WINDOW DEFOGGER RELAY OUTPUT
16 - -
17 - -
18 - -
19 - -
20 - -
21 - -
22 - -
23 - -
24 A31 12RD/BK IGNITION SWITCH OUTPUT (RUN-ACC)
25 F60 16RD/WT FUSED B(+)
26 - -
27 A41 12YL IGNITION SWITCH OUTPUT (START)
28 F14 20LG/YL FUSED IGNITION SWITCH OUTPUT (RUN-START)
29 A22 12BK/OR IGNITION SWITCH OUTPUT (RUN)
30 F991 18OR/DB FUSED IGNITION SWITCH OUTPUT (RUN-START)
31 Z234 20BK GROUND
32 F33 20PK/RD FUSED B(+)
33 X12 16WT/RD FUSED IGNITION SWITCH OUTPUT (RUN-ACC)
34 M1 20PK FUSED B(+)
35 M1 20PK (AZC) FUSED B(+)
36 A21 12DB IGNITION SWITCH OUTPUT (RUN-START)
37 - -
38 F70 20PK/BK FUSED B(+)
39 X3 20GY/OR HORN RELAY CONTROL
40 F30 16RD FUSED CIGAR LIGHTER RELAY OUTPUT
41 F33 20PK/RD FUSED B(+)
42 - -
43 V23 20BR/PK FUSED IGNITION SWITCH OUTPUT (RUN-ACC)
44 M1 20PK FUSED B(+)
45 Z132 20BK/OR GROUND
46 - -
47 - -
48 F70 20PK/BK FUSED B(+)
49 - -
50 G5 20DB/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
51 G5 20DB/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
52 F12 20DB/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
8W - 80 - 90 8W-80 CONNECTOR PIN-OUTWJ

JUNCTION BLOCK C4 - WHITE 2 WAY
CAV CIRCUIT FUNCTION
1 A148 10PK/WT FUSED B(+)
2 A148 10OR/WT FUSED B(+)
JUNCTION BLOCK C5 - WHITE 3 WAY
CAV CIRCUIT FUNCTION
1 A145 10WT/RD FUSED B(+)
2 A149 12RD/TN FUSED B(+)
3 A147 10RD/GY FUSED B(+)
KNOCK SENSOR - BLACK 4 WAY
CAV CIRCUIT FUNCTION
1 K4 18BK/LB SENSOR GROUND
2 K42 18DB/LG KNOCK SENSOR NO. 1 SIGNAL
3 K4 18BK/LB SENSOR GROUND
4 K142 18GY/BK KNOCK SENSOR NO. 2 SIGNAL
LEAK DETECTION PUMP (EXCEPT BUILT-UP-EXPORT)-4WAY
CAV CIRCUIT FUNCTION
1- -
2 K125 18OR/DG GENERATOR SOURCE
3 K106 20WT/DG LEAK DETECTION PUMP SOLENOID CONTROL
4 K107 20OR/YL LEAK DETECTION PUMP SWITCH SENSE
LEFT COURTESY LAMP - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 F70 20PK/BK FUSED B(+)
2 M2 20YL COURTESY LAMP DRIVER
WJ8W-80 CONNECTOR PIN-OUT 8W - 80 - 91

8W-97 POWER DISTRIBUTION
TABLE OF CONTENTS
page page
POWER DISTRIBUTION
DESCRIPTION..........................1
OPERATION............................1
SPECIAL TOOLS
POWER DISTRIBUTION SYSTEMS.........2
CIGAR LIGHTER OUTLET
DESCRIPTION..........................2
OPERATION............................2
DIAGNOSIS AND TESTING - CIGAR LIGHTER
OUTLET.............................2
CIGAR LIGHTER OUTLET DOOR SPRING
REMOVAL.............................3
INSTALLATION..........................3
IOD FUSE
DESCRIPTION..........................3
OPERATION............................4
REMOVAL.............................4
INSTALLATION..........................4
JUNCTION BLOCK
DESCRIPTION..........................5
OPERATION............................5
REMOVAL.............................5
INSTALLATION..........................6
POWER DISTRIBUTION CENTER
DESCRIPTION..........................7
OPERATION............................8
REMOVAL.............................8
DISASSEMBLY
POWER DISTRIBUTION CENTER
DISASSEMBLY........................9ASSEMBLY
POWER DISTRIBUTION CENTER
ASSEMBLY..........................11
INSTALLATION.........................12
POWER OUTLET
DESCRIPTION - FRONT POWER OUTLET....12
OPERATION - FRONT POWER OUTLET......12
DIAGNOSIS AND TESTING - POWER OUTLET . 12
REMOVAL.............................13
INSTALLATION.........................13
POWER OUTLET RELAY
DESCRIPTION.........................13
OPERATION...........................14
DIAGNOSIS AND TESTING - POWER OUTLET
RELAY..............................14
REMOVAL.............................15
INSTALLATION.........................15
IOD WIRE HARNESS CONNECTOR
DESCRIPTION.........................15
OPERATION...........................15
FUSE COVER
REMOVAL.............................16
INSTALLATION.........................16
REAR POWER OUTLET
DESCRIPTION - REAR POWER OUTLET.....16
OPERATION - REAR POWER OUTLET.......17
DIAGNOSIS AND TESTING - REAR POWER
OUTLET............................17
REMOVAL.............................17
INSTALLATION.........................18
POWER DISTRIBUTION
DESCRIPTION
This group covers the various standard and
optional power distribution components used on this
model. The power distribution system for this vehicle
consists of the following components:
²Power Distribution Center (PDC)
²Junction Block (JB)
²Power Outlets
The power distribution system also incorporates
various types of circuit control and protection fea-
tures, including:
²Automatic resetting circuit breakers
²Blade-type fuses
²Bus bars
²Cartridge fuses²Circuit splice blocks
²Flashers
²Fusible links
²Standard and Micro-Relays
Following are general descriptions of the major
components in the power distribution system. See the
owner's manual in the vehicle glove box for more
information on the features and use of all of the
power distribution system components. Refer to Wir-
ing Diagrams for complete circuit diagrams.
OPERATION
The power distribution system for this vehicle is
designed to provide safe, reliable, and centralized dis-
tribution points for the electrical current required to
operate all of the standard and optional factory-in-
stalled electrical and electronic powertrain, chassis,
safety, security, comfort and convenience systems. At
WJ8W-97 POWER DISTRIBUTION 8W - 97 - 1

the same time, the power distribution system was
designed to provide ready access to these electrical
distribution points for the vehicle technician to use
when conducting diagnosis and repair of faulty cir-
cuits. The power distribution system can also prove
useful for the sourcing of additional electrical circuits
that may be required to provide the electrical current
needed to operate accessories that the vehicle owner
may choose to have installed in the aftermarket.
NOTE: DO NOT ATTEMPT TO SWAP POWER DIS-
TRIBUTION CENTERS FROM ONE VEHICLE TO
ANOTHER. MOST OF THESE ASSEMBLIES ARE
VEHICLE FEATURE SPECIFIC AND THEREFORE
NOT INTERCHANGEABLE. ALWAYS USE THE COR-
RECT PART NUMBERED ASSEMBLY WHEN DIAG-
NOSING OR REPLACING A POWER DISTRIBUTION
CENTER.
SPECIAL TOOLS
POWER DISTRIBUTION SYSTEMS
CIGAR LIGHTER OUTLET
DESCRIPTION
A cigar lighter outlet is standard equipment on
this model. On models equipped with the optional
Smoker's Package, the cigar lighter knob and heating
element are included. On models without the Smok-
er's Package, the cigar lighter outlet is equipped with
a snap fit plastic cap and is treated as an extra
accessory power outlet. The cigar lighter outlet is
installed in the instrument panel center lower bezel,
which is located near the bottom of the instrument
panel center stack area, below the heater and air
conditioner controls. The cigar lighter outlet is
secured by a snap fit within the center lower bezel.The cigar lighter outlet, plastic cap and the knob
and heating element unit are available for service
replacement. These components cannot be repaired
and, if faulty or damaged, they must be replaced.
OPERATION
The cigar lighter consists of two major components:
a knob and heating element unit, and the cigar
lighter base or outlet shell. The receptacle shell is
connected to ground, and an insulated contact in the
bottom of the shell is connected to battery current.
The cigar lighter receives battery voltage from a fuse
in the junction block when the ignition switch is in
the Accessory or On positions.
The cigar lighter knob and heating element are
encased within a spring-loaded housing, which also
features a sliding protective heat shield. When the
knob and heating element are inserted in the outlet
shell, the heating element resistor coil is grounded
through its housing to the outlet shell. If the cigar
lighter knob is pushed inward, the heat shield slides
up toward the knob exposing the heating element,
and the heating element extends from the housing
toward the insulated contact in the bottom of the
outlet shell.
Two small spring-clip retainers are located on
either side of the insulated contact inside the bottom
of the outlet shell. These clips engage and hold the
heating element against the insulated contact long
enough for the resistor coil to heat up. When the
heating element is engaged with the contact, battery
current can flow through the resistor coil to ground,
causing the resistor coil to heat.
When the resistor coil becomes sufficiently heated,
excess heat radiates from the heating element caus-
ing the spring-clips to expand. Once the spring-clips
expand far enough to release the heating element,
the spring-loaded housing forces the knob and heat-
ing element to pop back outward to their relaxed
position. When the cigar lighter knob and element
are pulled out of the outlet shell, the protective heat
shield slides downward on the housing so that the
heating element is recessed and shielded around its
circumference for safety.
DIAGNOSIS AND TESTING - CIGAR LIGHTER
OUTLET
For complete circuit diagrams, refer toHorn/Ci-
gar Lighter/Power Outletin Wiring Diagrams.
(1) Check the fused B(+) fuse in the junction block.
If OK, go to Step 2. If not OK, repair the shorted cir-
cuit or component as required and replace the faulty
fuse.
(2) Turn the ignition switch to the On position.
Check for battery voltage at the fused B(+) fuse in
Terminal Pick Kit 6680
8W - 97 - 2 8W-97 POWER DISTRIBUTIONWJ
POWER DISTRIBUTION (Continued)

the junction block. If OK, go to Step 3. If not OK,
repair the open or short as required.
(3) Remove the cigar lighter knob and element
from the cigar lighter outlet shell. Check for continu-
ity between the inside circumference of the cigar
lighter outlet shell and a good ground. there should
be continuity. If OK, go to Step 4. If not OK, go to
Step 5.
(4) Turn the ignition switch to the On position.
Check for battery voltage at the insulated contact
located at the back of the cigar lighter outlet shell. If
OK, replace the faulty cigar lighter knob and ele-
ment. If not OK, go to Step 5.
(5) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the instrument panel center lower bezel.
Check for continuity between the ground circuit cav-
ity of the cigar lighter wire harness connector and a
good ground. There should be continuity. If OK, go to
Step 6. If not OK, repair the open ground circuit to
ground as required.
(6) Connect the battery negative cable. Turn the
ignition switch to the Accessory or On positions.
Check for battery voltage at the fused B(+) circuit
cavity of the cigar lighter wire harness connector. If
OK, replace the faulty cigar lighter outlet. If not OK,
repair the open fused B(+) circuit to the junction
block fuse as required.
CIGAR LIGHTER OUTLET
DOOR SPRING
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the instrument panel center lower
bezel from the I.P. Refer to Body for the procedure.
(3) Remove the cigar lighter outlet door spring
from its locating holes (Fig. 1).
INSTALLATION
(1) Install the cigar outlet door spring in its locat-
ing holes.
(2) Install the instrument panel center lower bezel
on the I.P. Refer to Body for the procedure.
(3) Connect the negative battery cable.
IOD FUSE
DESCRIPTION
All vehicles are equipped with an Ignition-Off
Draw (IOD) fuse (Fig. 2) that is removed from its
cavity in the Power Distribution Center (PDC) when
the vehicle is shipped from the factory. Dealer per-sonnel are to remove the IOD fuse from the storage
location and install it into PDC fuse cavity 15 as part
Fig. 1 Cigar Lighter Outlet Door Spring
1 - CIGAR LIGHTER OUTLET
2 - CIGAR LIGHTER OUTLET DOOR SPRING
Fig. 2 Ignition-Off Draw Fuse
1 - POWER DISTRIBUTION CENTER
2 - IGNITION-OFF DRAW FUSE
3 - IOD FUSE STORAGE CAVITY
WJ8W-97 POWER DISTRIBUTION 8W - 97 - 3
CIGAR LIGHTER OUTLET (Continued)

JUNCTION BLOCK
DESCRIPTION
An electrical Junction Block (JB) is concealed
beneath the driver side of the instrument panel in
the passenger compartment of the vehicle (Fig. 3).
The JB combines the functions previously provided
by a separate fuseblock module and relay center. The
JB serves to simplify and centralize numerous elec-
trical components, as well as to distribute electrical
current to many of the accessory systems in the vehi-
cle. It also eliminates the need for numerous splice
connections. The JB houses up to thirty-three blade-
type mini fuses, up to two blade-type automatic
resetting circuit breakers, the electronic combination
flasher, the Daytime Running Lamp (DRL) module
(Canada only) and up to twelve International Stan-
dards Organization (ISO) relays (three standard-type
and nine micro-type). The JB also incorporates an
integral connector and mounting for the Body Con-
trol Module (BCM). The BCM is secured with four
screws directly to the dash panel side of the JB.
Refer toBody Control Modulein Electronic Con-
trol Modules for additional information covering the
BCM.
The molded plastic JB housing has integral mounts
that are secured with two screws and two snap
retainers to the instrument panel steering column
support bracket behind the instrument panel steer-ing column opening cover. The JB is concealed above
the molded plastic instrument panel fuse cover. Inte-
gral latches molded into the fuse cover secure it the
JB, the BCM and the 16-way data link connector tab
of the instrument panel steering column support
bracket. The fuse cover can be pulled downward to
disengage the latches and provide service access to
all of the fuses, relays and wire harness connectors of
the JB. The fuse cover has a fuse puller and spare
fuses secured to its upper surface. Refer toInstru-
ment Panel Fuse Coverin Body for additional ser-
vice information.
The JB unit cannot be repaired and is only ser-
viced as an assembly. If any internal circuit or the JB
housing is faulty or damaged, the entire JB unit
must be replaced. The BCM is available for separate
service replacement.
OPERATION
All of the circuits entering and leaving the Junc-
tion Block (JB) do so through up to five wire harness
connectors, which are connected to the JB through
integral connector receptacles molded into the JB
housing. Internal connection of all of the JB circuits
is accomplished by a printed circuit board. There are
also two separate wire harness connections to con-
nector receptacles that are integral to the BCM.
Refer toJunction Blockin Wiring Diagrams for
additional information and the location of complete
JB circuit diagrams.
REMOVAL
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE AIRBAG SYSTEM. FAILURE TO TAKE
THE PROPER PRECAUTIONS COULD RESULT IN
ACCIDENTAL AIRBAG DEPLOYMENT AND POSSI-
BLE PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the fuse cover from the bottom of the
Junction Block (JB).
(3) Remove the steering column opening cover
from the instrument panel. Refer toSteering Col-
umn Opening Coverin Body for the location of
steering column opening cover removal procedures.
Fig. 3 Junction Block Location
1 - REAR LATCHES
2 - JUNCTION BLOCK AND BODY CONTROL MODULE UNIT
3 - INSTRUMENT PANEL FUSE COVER
4 - SIDE LATCH
5 - FRONT LATCHES
WJ8W-97 POWER DISTRIBUTION 8W - 97 - 5